This invention relates to a non-circular gear pair, and to an angular velocity modulating device with the non-circular gear pair or pairs, which may be used to provide a non-step variable transmission applicable to power plants.
In order to provide a mechanical non-step variable transmission, a gear device and an angular velocity modulating device have been disclosed, for instance, Japanese Patent Application (OPI) No's 266866/1986 and 270863/1987. In the conventional device, three or four non-circular external gears forming an intermeshing pitch curve in such a manner as to exponentially change (increase or decrease) the speed ratio are combined as an elementary unit, and a plurality of the elementary units thus provided are used to form the non-step variable transmission.
The above-described conventional angular velocity modulating device is disadvantageous in that it is unavoidably large in a radial direction because all of the non-circular gears forming each elementary unit are external gears.